


For an Experiment

by potentiallyAWKWARD



Category: Sherlock (TV)
Genre: In Ross Geller voice: "It was for an experiment!", John thinks that Sherlock is suicidal but he isn't, M/M, Mutual Wanking
Language: English
Status: Completed
Published: 2017-02-14
Updated: 2017-02-14
Packaged: 2018-09-24 10:08:58
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,812
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9717095
Author URL: https://archiveofourown.org/users/potentiallyAWKWARD/pseuds/potentiallyAWKWARD
Summary: John refuses to leave Sherlock's side, which gets awkward when Sherlock requests to have his biweekly wank.





	

**Author's Note:**

> My parents didn't want to let me stay home alone his weekend, most likely because they were afraid I might hurt myself, but really I just wanted to get on PornHub unhindered. So the first line of this story popped into my head and the rest is history.

"I'm not suicidal, just horny," Sherlock huffed, rolling his eyes.

My mouth opened and closed several times as question after question rolled through my head. Finally, I decided to go with the safest one: "What?"

Sherlock perched himself on the edge of his bed, flipping the end of his belt out of his trouser loop. "Of course that's the logical assumption. I just got out of the hospital after suffering a self-induced- and may I add again ACCIDENTAL- drug overdose and you're unwilling to let me leave your sight. So, when I request in a moment that you leave my room for nineteen minutes and forty-two seconds, I am reaffirming the fact that I am not going to 'finish the job' and off myself, rather, perform my bi-weekly check and tune up."

My jaw worked as slowly, the rapid fire words sunk into my brain. "It was half a bottle of paracetamol, Sherlock, what are we supposed to think?"

Sherlock rolled his eyes, popping open the top button to his trousers. "I'll say it again: I didn't calculate the effect coffee would have on the paracetamol."

I pinched the bridge of my nose. "You downed a dozen tablets then drank an entire pot of coffee. Why would you do that if it wasn't a suicide attempt?"

"It was for an experiment," Sherlock huffed, unzipping his trousers. My eyes darted down for a split second before I caught myself. 

"Does this have to be now?" I asked, shifting uncomfortably.

"Yes. Every other Wednesday, I retreat to my room exactly nineteen minutes earlier than usual to do this. I'm not going to skip this one just because you find it inconvenient. Now leave."

"Are you telling me there's absolutely nothing dangerous in your entire bedroom?" I asked skeptically, already knowing the answer.

"For God's sake, John, are you really going to stand here while I rub one out?" Sherlock sighed, running a hand through his black curls.

"I would turn away, but it only takes a split second of unsupervision," I affirmed. Half of me wondered why I was being so bloody stubborn about this, but the other half knew perfectly well why.

As if reading my mind, one of Sherlock's perfectly sculpted eyebrows went up, but he didn't comment. Instead, he stood and slowly pulled off his trousers, gracelessly kicking them off. They landed in a heap on the floor, and I kept my eyes determined trained on them instead of my now half-naked flatmate.

"Are you sure you don't want to leave?" Sherlock finally asked once he had sprawled himself across his bed, legs obscenely spread. I swallowed. I was getting a feeling that Sherlock was not, in fact, going to hurt himself; rather, quite the opposite. Just the same- it would be best that I ensured- wasn't it?

"I'm not leaving," I reaffirmed. I widened my stance, eyes shifting finally to Sherlock's face, suddenly and intensely glad I had worn my slightly baggier jeans today.

Sherlock smirked, eyes alight. "I'm going to reach into my nightstand. Just getting... things."

I nodded tersely as he slowly slid the drawer open and dug around in it, obviously relishing the attention. Finally, with flourish, he procured a small tube of lubricant and-

Oh.

I felt my face heat up as Sherlock pulled a vibrator out of his drawer. Jesus Christ, this wasn't part of the agreement.

"Not too late," Sherlock smirked. Challenged.

I sniffed, willing my cock to behave. I had to keep in mind the reason that I was in this situation at all. "I'm not leaving," I said again. The corner of Sherlock's mouth twitched.

"Suit yourself. There is a reason I do this, you know," he continued conversationally as he squirted a fair amount of lube onto his palms- water based, I expected something more posh- and warmed it. "Check for lumps or other signs of testicular cancer, bulging or swelling in my prostate, consistency of my ejaculate."

I hummed noncommittally, bouncing on the balls of my feet and looking to his poster of the Periodic Table of Elements.

From the corner of my eyes, I could see his fingers slowly kneading and rolling his bollocks, one then the other. They were heavy and hairless- shit, now I was looking, wasn't I?- and just the right size to fit in my mou-

I cleared my throat, cock stirring. This was going to be harder than I anticipated. I tried to remind myself that he was mentally unwell, but deep down I knew that this afternoon wasn't really a suicide attempt, just a mistake on his part that had serious repercussions.

After about five minutes of his gentle, thorough kneading, his hands went to his navel and rested. "No signs of cancer," Sherlock reported, slightly breathless. His impossibly grey eyes met mine; his pupils were dilated. Not that I needed any more proof that he was aroused; his cock was half-hard and he hadn't even touched it.

He got a bit more lube and slowly fisted his cock, flinching slightly at the coolness of the liquid but nonetheless sliding his hand down his shaft. His mouth opened slightly as his eyes closed, and that clever tongue darted out and licked his bottom lip.

Despite my best efforts, my jeans were getting a bit uncomfortable, and my cheeks were a shade pinker than usual. He hadn't even started yet and I was achingly hard; harder than the detective, at any rate.

Slowly, he pulled his fist back up, thumb sweeping over the tip of his cock, causing a quiet hiss to escape his lips. Sherlock's eyes snapped open suddenly and he leaned forward, maintaining eye contact with me as he pursed his lips and let a glob of spit fall out of his mouth and directly onto the head of his cock. It began to run down the side of his shaft until his first caught it, sweeping it up and over his tip with another brush of his long, slender thumb.

My knees went weak and my breath hitched in my throat. Sherlock smirked at me, a slow, sexy smirk that was dark and promising. His pupils were nearly eclipsing the irises now; his eyes flickered down to my rather obvious bulge and back up. Without thought, I reached down and unzipped my trousers, pulling my pants out and over my cock and letting my erection spring free. Sherlock's smile widened.

His hand, which had been working quickly, slowed as he reached down with his other hand to his puckering hole, lifting his knees and planting his feet closer to his body. It was quite a nice view.

I held my hand to my mouth and spit, far less gracelessly than Sherlock had done but no less effective, palming my aching cock and stroking firmly. Sherlock's eyes darted down as his mouth gaped slightly, his teeth biting down into his soft-looking lower lip. His finger slowly traced his hole, slowly dipping in the the first digit and then it was back out, circling again.

His hand paused around his cock, letting his finger rub his slit for a moment. I could see precum beginning to seep down the side of his shaft and I had the sudden, intense urge to lean forward and lap it up.

And his index finger was dipping back in, this time to the second digit; I could see him tense slightly around the intrusion but then he was relaxed again as he slowly pumped his finger in and out of himself, resuming his steady stroking of his cock.

And then his entire index finger was gone, sheathed deep inside Sherlock, and he let out a breathy gasp, twisting his wrist slightly. He pumped it in and out of himself for a minute, face screwed up in concentration as his wrist twisted impossibly, at least into an uncomfortable position if not bone-crushing, and then his hips were off the mattress and his cock was twitching helplessly, a moan ripping out of his throat.

His middle finger joined his first, wrist relaxing back to a normal position and moving frantically in and out of himself. From several feet away I could see lubricant streaming over the edge of his sphincter and down into the mattress and I longed for my mouth to be there instead of his hands; a revelation that made my eyes snap shut and sweat bead on my forehead. Okay, so I was officially admitting to myself that I had feelings for Sherlock, then.

For someone who didn't have much experience in anal sex, it seemed to me like he was moving much too quickly; a third finger was added, and they spread apart and back together, stretching him out enough for his toy. His hand had stilled around his cock, instead letting his hips snap up and into his fist. His head was red and swollen, a steady stream of precum dripping down over the knuckle of his thumb.

Then both hands were fumbling with the lube again, and he was pumping the dildo with his hand, getting it nice and wet so it could make an easier entrance. Without hesitation he plunged it into himself and his cock twitched, a small sigh escaping his lips as he pressed the button to turn on the vibrator.

His mouth opened silently, face screwed up as he twisted his wrist again, plunging the toy in and out of himself. He cried out, his legs stiffening as he held it deep inside himself. Obviously he'd found his prostate, and then his hand was flying over his cock, making an obscene sound really, skin on skin and wet, his hand was a blur as his hips lifted off the bed once, twice-

-and he cried out, high and keening, head thrashing as cum spurted out of his cock, trailing the sticky substance down his knuckles and shaft and down his perineum, and my hips were snapping into my fist, seeking friction- and I was getting closer-

"Fuck, John," Sherlock moaned.

-and I was spiraling, spiraling, my mouth opened and maybe I made a sound, but maybe not; hot, wet semen all over my hand and down the front of my trousers, knees wobbling-

After a few minutes, I finally opened my eyes, finding Sherlock still spread out, all traces of his sexual activity gone except for the cooling semen splattering his navel and down his bollocks. His eyes were serene and calculating. Finally: "No swelling in my prostate except that due to sexual arousal."

And I was laughing, and he was laughing; we laughed for a few minutes, both covered in our own sex, until I finally broke the amicable silence: "You know, next time you want to wank in front of me, you don't need to go through the trouble of an overdose."

"It was for an experiment!"

**Author's Note:**

> I think of Sherlock saying "It was for an experiment!" in the same voice that Ross Geller from Friends says "We were on break!"


End file.
